2-{2-chloro-4-mesyl-3-[(tetrahydrofuran-2-ylmethoxy)methyl]benzoyl}cyclohexane-1,3-dione

Toxicity to soil macroorganisms except arthropods

Link to relevant study record(s)

Reference

Endpoint:

toxicity to soil macroorganisms except arthropods: short-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

21 Aug 2002 – 04 Sep 2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 207 (Earthworm, Acute Toxicity Tests)

Version / remarks:

1984

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Details on preparation and application of test substrate:

- Method of mixing into soil (if used): To obtain fresh stock solution for the test, the test item was weighed out to a precision of 0.1 mg and mixed in industrial sand. 10 g stock mixture were added to the basic substrate in the mixing vessel and mixed thoroughly with a rapid mixer (740 g basic substrate + 10 g stock mixture = 750 g test substrate). After mixing, the test substrates were filled into the respective test jars.
- Test concentrations: The test was conducted with 100, 180, 320, 560 and 1000 mg/kg dry artificial soil.

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Details on test organisms:

TEST ORGANISM
- Common name: Eisenia fetida
- Age at test initiation (mean and range, SD): In the test only adult animals, older than 2 months and showing a clitellum were used.
- Weight at test initiation (mean and range, SD): 5.01 -5.51 g

ACCLIMATION
- Acclimation period: 24 h
- Acclimation conditions (same as test or not): same as test

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

no

Total exposure duration:

14 d

Test temperature:

20 ± 2 °C

pH:

6.1 - 6.2 at study initiation and 6.0 - 6.1 after 14 days of study duration.

Moisture:

25.5 and 25.3% at experimental start and study termination

Details on test conditions:

TEST SYSTEM
- Test container (material, size): The test was conducted in 1.5 L glass jars. The jars had a diameter of about 10 cm and a height of about 20 cm (approximate values of internal dimensions). The vessels were covered with glass lids.
- Amount of soil or substrate: Each test container was filled with 750 g of test substrate.
- No. of organisms per container (treatment): 10
- No. of replicates per treatment group: 4
- No. of replicates per control: 4

SOURCE AND PROPERTIES OF SUBSTRATE
- Composition (if artificial substrate): 10% sphagnum peat (dried and sifted, 10.3% residual moisture), 70% industrial sand, 20% kaolin clay. 80g Calcium carbonate were added to this mixture.
- Pretreatment of soil: After blending the moisture content of this basic substrate was determined by means of a scale with a drying device. The residual moisture content of this substrate was 1.4 percent. After addition of 5.4 L deionised water and blending the actual moisture content was determined at 25.9 % (equivalent to a moisture content of about 35 % based on dry weight).

OTHER TEST CONDITIONS
- Photoperiod: constantly illuminated
- Other: The worms were not fed during the 14 day testing period.
- Test conditions: Temperature was recorded continuously in the climatic chamber during the whole test period. The moisture content of the test substrate (untreated control) and the weight of living worms were determined at the start and the end of testing. The pH of the test substrate was measured at the start and at the end of testing in one replicate at each treatment level.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable):
- Mortality: was assessed after 7 and 14 days
- Body weight: was measured at start and at the end of the test

Nominal and measured concentrations:

Nominal: 100, 180, 320, 560 and 1000 mg/kg dry artificial soil

Reference substance (positive control):

yes

Remarks:

Chloroacetamide

Duration:

14 d

Dose descriptor:

LC50

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Details on results:

- Mortality and sublethal effects at end of exposure period: No mortality, no intoxication symptoms and no significant weight differences compared to the control or any adverse effect was observed in any treated group up to and including 1000 mg/kg.

Results with reference substance (positive control):

LC50 (7 d): 24.0 mg/kg soil dw (test performed June 19 to July 03, 2001)

Reported statistics and error estimates:

Mean individual weight per group at the start of the test and weight difference between start and end of the test were compared by statistical analysis, employing Analysis of Variance, General Linear Models, DUNCAN'S Multiple Range Test and DUNNETTs Test Procedures (SAS, 1989).

Table 1: Mortality, symptoms and body weights

 

Nominal concentration (mg/kg)	Mortality (%)		Weight change (%)	Symptoms
	Day 7	Day 14	Day 0 - 14	Day 7 & 14
Control	0	0	-6.0	-
100	0	0	-7.1	-
180	0	0	-4.3	-
320	0	0	-7.2	-
560	0	0	-7.9	-
1000	0	0	-9.3	-
LC50 (mg/kg dry soil)	>1000	>1000	NOEC > 1000 mg/kg dry soil

 

 

 

Table 2: Validity criteria for OECD 207 (1984)

 

Criterion	Outcome	Criterion fulfilled
Mortality in the control≤10 % at the end of the test	0%	yes

 

Validity criteria fulfilled:

yes

Remarks:

See Table 2 in "Any other information on results incl. tables".

Description of key information

The short-term LC50 for the soil macroorganisms except arthropods (Eisenia fetida) is ≥1000 mg/kg dry weight soil.

Key value for chemical safety assessment

Short-term EC50 or LC50 for soil macroorganisms:

1 000 mg/kg soil dw

Additional information

In the available GLP study, the short-term toxicity of tefuryltrione to earthworms (Eisenia fetida) was investigated after 14-day exposure according to OECD guideline 207. The earthworms were exposed to test substance concentrations of 100, 180, 320, 560 and 1000 mg/kg dry artificial soil, alongside a control. The no-observed-effect-concentration (NOEC) with no mortality, no intoxication symptoms and no significant weight decrease compared to the control was ≥1000 mg test item/kg dry artificial soil. Thus, the LC50 is≥1000 mg test item/kg dry artificial soil.